Synphilin-1 (SNCAIP)

Isoform 2 inhibits the ubiquitin ligase activity of SIAH1 and inhibits proteasomal degradation of target proteins. Isoform 2 inhibits autoubiquitination and proteasomal degradation of SIAH1, and thereby increases cellular levels of SIAH.

Isoform 2 modulates SNCA monoubiquitination by SIAH1. .